1. Field of the Invention
The present invention relates generally to a head assembly and disk drive having same.
2. Description of the Related Art
Generally, a hard disk drive has a head assembly positioned at the tip of an arm driven by an actuator. The head assembly is composed of a head slider mounted on a suspension together with an integrated circuit, or IC, chip. The head slider has a magnetic head formed using thin film technology. The magnetic head is composed of an inductive head and a magneto-resistive head, hereinafter referred to as an MR head. The inductive head writes information to a hard disk and the MR head reads recorded information from the hard disk. The head IC chip has the function of, for example, amplifying a microsignal read by means of the MR head.
Attendant upon recent improvements, that is, increases, of the frequency of the data signals handled by data processing devices, there is a demand for hard disk drives capable of reading and writing high data-signal frequencies of for example 200-300 MHz, well in excess of the current 70 MHz standard. As can be appreciated by those skilled in the art, raising the data signal write frequency necessitates increasing the data signal transfer rate. Increasing the data signal transfer rate in turn requires physically reducing the distance from the head slider to the IC chip, thus minimizing inductance and electrostatic capacitance along the signal transmission path between the head slider and the head IC chip.
Additionally, the head assembly must be one that can be produced using production techniques currently in use or under development.
FIGS. 1A and 1B show a head assembly 10 described in Japanese Laid-Open Patent App. No. 10-124839. A head slider 11 is joined to a head IC chip 12 and the head IC chip 12 is fixedly mounted on a suspension 13.
The head IC chip 12 comprises a lower surface 12a, an integrated circuit part and a wire pattern (neither of which is shown in the drawing), an electrode 16, an upper surface 12b and another electrode 17, the electrodes 16 and 17 being connected by a through hole 18.
The head slider 11 is affixed to the lower surface 12a of the IC chip 12 using an adhesive agent 19. The electrodes 15 and 16 are electrically connected to each other. A flexible cable 20 is affixed to the upper surface 12b of the head IC chip 12 using another adhesive agent 21. The electrode 17 and an electrode 22 of the flexible cable 20 are electrically connected to each other.
According to the above-described head assembly 10, the physical distance separating the head slider 11 and the head IC chip 12 is essentially eliminated, making it possible to greatly increase the transfer rate of the data signal.
However, referring to the head IC chip 12, it can be appreciated that the electrode 17 must be formed on a surface opposite a surface on which the integrated circuit part is formed, and, further, one or more holes must be opened in a silicon wafer to form one or more through holes 18. Yet the formation of the electrode 17 on the surface opposite the surface on which the integrated circuit part is formed and the opening of one or more holes in a silicon wafer is either very difficult or virtually impossible, and accordingly, the head IC chip 12 described above is essentially impossible to produce.
Additionally, referring to the common method by which the head slider 11 is produced, it should be noted that, as shown in FIG. 2, a plurality of magnetic heads 14 are arranged in the form of a matrix on a surface 26 of a wafer 25. The wafer 25 is then cut along the matrix so as to cut out individual sliders 11. As can be appreciated, the electrode 15 on the head slider 11 as shown in FIG. 1B is formed on a surface different from the surface on which the magnetic head 14 is formed. The surface on which the electrode 15 is formed is not the surface 26 of the wafer 25 but is instead the surface that first appears once the wafer 25 has been cut along the matrix and the individual sliders 11 cut out. Accordingly, the electrodes 15 are formed on each individual slider 11 cut from the wafer 25. Additionally, the length of the longest side is small, that is, approximately 1 mm. Accordingly, it is very difficult to form the electrodes 15 on the surfaces of individual head sliders 11 and hence it is exceedingly difficult and substantially impossible to produce the head slider 11.
Accordingly, the head assembly 10, too, is essentially impossible to mass produce.
Additionally, referring to the adhesive agent 19, it can be appreciated that because the adhesive agent 19 is injected into a gap between the head slider 11 and the head IC chip 12 after electrodes 15 and 16 have been connected to each other, there is a possibility that air bubbles may be trapped therewithin, thus reducing the strength of the bond between the head slider 11 and the head IC chip 12.
Accordingly, it is a general object of the present invention to provide an improved and useful head assembly and disk drive having same, wherein the foregoing problems are eliminated,
Another object of the present invention is to provide an improved and useful head assembly and disk drive having same, wherein the head assembly can be produced without undue difficulty.
Still another object of the present invention is to provide an improved and useful head assembly and disk drive having same, wherein the bonding of the head slider to the head IC chip is improved.
The above-described objects of the present invention are achieved by a head assembly comprising:
a head slider including a magnetic head and a first electrode;
an IC chip supporting the head slider on a principal surface of the IC chip; and
a suspension supporting the IC chip, the IC chip comprising a second electrode and a third electrode on the principal surface thereof, the third electrode being connected to the suspension, the second electrode being electrically connected to the first electrode.
Additionally, the above-described objects of the present invention are also achieved by a disk drive comprising:
a recording medium;
an arm driven by an actuator; and
a head assembly that rotates together with the arm,
the head assembly comprising:
a head slider including a magnetic head and a first electrode;
an IC chip supporting the head slider on a principal surface of the IC chip; and
a suspension supporting the IC chip,
the IC chip comprising a second electrode and a third electrode on the principal surface thereof, the third electrode being connected to the suspension, the second electrode being electrically connected to the first electrode.
Additionally, the above-described objects of the present invention are also achieved by an IC chip, the IC chip supporting a head slider including a magnetic head and a first electrode on a principal surface of the IC chip, a suspension supporting the IC chip, the IC chip having a size larger than a size of the head slider, the principal surface of the IC chip including an area for supporting the head slider and a second electrode electrically connected to the first electrode of the head slider and a third electrode electrically connected to the suspension, the second electrode and the third electrode provided at an area outside the area for supporting the head slider.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.